Wear and corrosion resistant properties of electrodeposited Ni composite coating containing Al2O3-TiO2 composite powder

Electrodeposited Ni composite coatings containing ceramic particles have been widely investigated due to their improved mechanical, wear and corrosion resistant properties over plain nickel coatings. The application of one of the most widely studied plasma spray powder, Al2O3–13 wt-%TiO2, has not been explored in electrodeposited nickel composites. In the present study, Ni/Al2O3–13 wt-%TiO2 coatings have been electrodeposited using physically mixed commercial Al2O3 and TiO2 powders. The microhardness, wear and corrosion resistant properties of the coatings have been investigated. It was found that the area fraction of particles incorporated in the nickel matrix was very high at lower current density, and the corresponding composite coating exhibited a maximum microhardness (∼580 HK). Interestingly, corrosion resistance of Ni/Al2O3–13 wt-%TiO2 composite coating was similar to that reported for Ni/TiO2. The wear behaviour of Ni/Al2O3–13 wt-%TiO2 coating was in between Ni/Al2O3 and Ni/TiO2 coatings and thus exhibited a synergistic effect of the properties of Al2O3 and TiO2 powders

Reclamation of thermal power plant waste as a distributed phase in electrodeposited Ni composite coating

In the exploration for newer and inexpensive distributed phases that can be used in electrodeposited Ni-composite coatings, cenosphere particles which are one of the constituents of fly ash, the waste product of thermal power plants has been explored as a potential candidate material. An attempt was made to prepare electrodeposited Nicenosphere composite coating. The as-received cenosphere particles could be codeposited only after reducing the particle size by ball milling. The loading of cenosphere particles in the Ni-sulphamate bath was varied (25, 75 and 100 g L−1) and a maximum microhardness of 430 HK at 50 gF load was obtained for the coating deposited from 100 g L−1 cenosphere containing bath. The Ni-cenosphere composite coating with higher microhardness exhibited lower wear rate. Thus cenosphere, a waste product from thermal power plants is a potential candidate for a greener surface engineering strategy for improving the wear resistance of electrodeposited Ni composite coating

Fabrication of Superhydrophobic Zinc Stearate Hierarchical Surfaces from Different Precursors

The fabrication of zinc stearate superhydrophobic hierarchical surfaces from two precursors by a simple wet chemical route and its wettability is reported. The zinc stearate coatings were prepared from a single pot using ethanolic solutions of zinc acetate/zinc nitrate and stearic acid. The coatings were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, water contact angle, and sliding angle measurements. The coatings obtained from zinc acetate precursor showed superhydrophobicity (WCA >150°) even at lower precursor concentrations. The morphology of the coatings varied with the nature as well as the concentration of the precursors

In-vitro corrosion studies of plasma sprayed hydroxyapatite coatings fabricated from coprecipitation synthesized powder

Plasma sprayed bioactive hydroxyapatite (HAp) implants on Ti-6Al-4V substrates have been widely used in load-bearing applications because of their biocompatibility and their intimate contact with bone. In the present study, plasma sm. The present paper discusses detailed corrosion behavior of uncoated and hydroxyapatite coated Ti-6Al-4V in simulated body fluid (Hanks` solution) condition. The HAp coated sample exhibited a smoother anodic curve when compared to uncoated substrate suggesting an improved passive nature of the coated surface. The icorr values for the uncoated and HAP coated samples were found to be 20 μA cm-2 and 14 μA cm-2 respectively. Electrochemical impedance spectroscopy studies showed that the HAp coating applied on to the Ti-6Al-4V alloy does not degrade the corrosion protection of the surface but instead offers an improvement to it.m. HAp coating was deposited on Ti-6Al-4V substrate using atmospheric air plasma spraying system. The as synthesized powder exhibited 97% crystallinity, whereas the coating exhibited a crystallinity of 76%. The coating thickness was ~100 µm and it consisted of mostly fully melted regions and unmelted/partially melted regions. The coating exhibited a surface roughness of 5.7 prayable grade hydroxyapatite powder was prepared by co-precipitation technique using mixture of precipitating agents and avoiding agglomeration process like spray drying. The powder possessed good flowability and exhibited an average agglomerated size of 8

Interactions among genes in the ErbB-Neuregulin signalling network are associated with increased susceptibility to schizophrenia

<p>Abstract</p> <p>Background</p> <p>Evidence of genetic association between the NRG1 (Neuregulin-1) gene and schizophrenia is now well-documented. Furthermore, several recent reports suggest association between schizophrenia and single-nucleotide polymorphisms (SNPs) in ERBB4, one of the receptors for Neuregulin-1. In this study, we have extended the previously published associations by investigating the involvement of all eight genes from the ERBB and NRG families for association with schizophrenia.</p> <p>Methods</p> <p>Eight genes from the ERBB and NRG families were tested for association to schizophrenia using a collection of 396 cases and 1,342 blood bank controls ascertained from Aberdeen, UK. A total of 365 SNPs were tested. Association testing of both alleles and genotypes was carried out using the fast Fisher's Exact Test (FET). To understand better the nature of the associations, all pairs of SNPs separated by ≥ 0.5 cM with at least nominal evidence of association (<it>P </it>< 0.10) were tested for evidence of pairwise interaction by logistic regression analysis.</p> <p>Results</p> <p>42 out of 365 tested SNPs in the eight genes from the ERBB and NRG gene families were significantly associated with schizophrenia (<it>P </it>< 0.05). Associated SNPs were located in ERBB4 and NRG1, confirming earlier reports. However, novel associations were also seen in NRG2, NRG3 and EGFR. In pairwise interaction tests, clear evidence of gene-gene interaction was detected for NRG1-NRG2, NRG1-NRG3 and EGFR-NRG2, and suggestive evidence was also seen for ERBB4-NRG1, ERBB4-NRG2, ERBB4-NRG3 and ERBB4-ERBB2. Evidence of intragenic interaction was seen for SNPs in ERBB4.</p> <p>Conclusion</p> <p>These new findings suggest that observed associations between NRG1 and schizophrenia may be mediated through functional interaction not just with ERBB4, but with other members of the NRG and ERBB families. There is evidence that genetic interaction among these loci may increase susceptibility to schizophrenia.</p

Non-solvolytic synthesis of aqueous soluble TiO2 nanoparticles and real-time dynamic measurements of the nanoparticle formation.

Highly aqueously dispersible (soluble) TiO2 nanoparticles are usually synthesized by a solution-based sol-gel (solvolysis/condensation) process, and no direct precipitation of titania has been reported. This paper proposes a new approach to synthesize stable TiO2 nanoparticles by a non-solvolytic method - direct liquid phase precipitation at room temperature. Ligand-capped TiO2 nanoparticles are more readily solubilized compared to uncapped TiO2 nanoparticles, and these capped materials show distinct optical absorbance/emission behaviors. The influence of ligands, way of reactant feeding, and post-treatment on the shape, size, crystalline structure, and surface chemistry of the TiO2 nanoparticles has been thoroughly investigated by the combined use of X-ray diffraction, transmission electron microscopy, UV-visible (UV-vis) spectroscopy, and photoluminescence (PL). It is found that all above variables have significant effects on the size, shape, and dispersivity of the final TiO2 nanoparticles. For the first time, real-time UV-vis spectroscopy and PL are used to dynamically detect the formation and growth of TiO2 nanoparticles in solution. These real-time measurements show that the precipitation process begins to nucleate after an initial inhibition period of about 1 h, thereafter a particle growth occurs and reaches the maximum point after 2 h. The synthesis reaction is essentially completed after 4 h.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Multifaceted incorporation of Zn-Al2O3/Cr2O3/SiO2 nanocomposite coatings: anti-corrosion, tribological, and thermal stability

Nano-sized particle incorporation into metal matrix has gained worldwide acceptance. Al2O3, Cr2O3, and SiO2 nanoparticles have been co-deposited with Zn using electrodeposition process to produce advanced alloy. The coatings were characterized using SEM/EDX and XRD. The mechanical properties of the coatings were studied using microhardness indenter and dry abrasive wear tester. Zn-10 g/L Cr2O3 nanocomposite exhibited the highest microhardness of 228 HVN; Zn-5 g/L Al2O3 nanocomposite possessed the highest corrosion resistance and lowest wear loss. Zn-5 g/L SiO2 nanocomposite showed good stability against other composite coatings. The incorporation of the Al2O3, Cr2O3, and SiO2 shows grain refinement and modify orientation on Zn matrix